Usually, it’s easier to first take the whole family + sibling pictures because the older child/children have more energy in the beginning. It is good to take some activities (books, toys, the possibility to watch cartoons etc.) for the older child/children for the rest of the photo shoot if they also stay with us for the rest of the time and don’t have a babysitter. I know it is not always so simple to arrange the babysitting so your other child/children are absolutely welcome. You can explain to the sibling/s that we will first visit an exciting photo studio to take some cool family pictures, and after that, you will get to do some own calm activities as mom and dad are with the baby taking some more pictures.